What is K? Color Temperature and Kelvin
“Kelvin” is a basic unit of thermodynamic temperature (color temperature) used to measure the hue (color) of the light output. Typical HID kits are offered in 3000K – 20000K color ranges. Of that color range, the most popular HID colors are 6000k and 8000k. Pay attention to this: The higher the Kelvin (K) of the kit, the bluer the light output is… The Kelvin number DOES NOT mean the light is brighter! The ideal driving ranger from an HID kit would be between 4300k to 6000k. The light output of a 4300k kit is the closest replication of sunlight, which is the ideal driving light. Kits in the higher Kelvin range, 1000K +, are so blue that the light tends to scatter before hitting the road, making the light output less efficient. Also, due to the high color saturation, the light will not project as far as the 4300k and 6000k kits. Although this adds a great look to the vehicle, it is not the most effective in the way of lighting.
The below, HID color chart, gives you an idea of the range of light that you could expect from each of the kelvin temperatures.
Warm Colors vs. Cool Colors
Warm colors are colors in the red to the white range, including yellow and orange hues. Warm colors have a lower Kelvin rating than cool colors. For example, 4300k is considered a warm color, and the light output is white/yellow. This does not mean that HID lamps with warm colors are less bright than colors with a higher Kelvin rating.
- Cool colors include bluish whites, blues, and indigo shades. They have higher Kelvin ratings than warm colors. HID lamps with cool colors may produce less usable light than bulbs with warmer colors. For example, 10000k is a cool color and tends to produce less light than warm colors.
If you want the brightest light possible, get the 4300k or 6000k kit
- 3000k HIDs emit yellow light. These are often used in place of halogen fog lamps.
4,300 Kelvin indicates a white light with a yellow tint. It is fairly close in color to sunlight which is the most ideal driving light. In HID lamps, this color gives the most visible light and it most often the color choice in OEM hid kits.
Installed: 4300k HID Lights on a Chevy Suburban
6,000 Kelvin is almost pure white but has a very faint tint of blue. HID lamps with this rating have a very high performance, although they don’t give off quite so much visible light as 4,300 Kelvin lamps. This color is very popular as an aftermarket option. Note: I personally think this color looks best… 95% white with 5% blue makes for a super crisp/clean looking light.
Installed: 6000k HID Lights on a Scion TC.
HID lamps with an 8,000k rating give off a pale blue light and offer less visual light than 4300k and 6000k kits. This is my second favorite choice for aftermarket HIDs. The light looks great and the light output is not too far off the 6000k kits.
HID bulbs with a 10,000k rating give off a deep blue light. The brightness and the performance of the lamp as a light source is significantly lower than a 4,300 Kelvin lamp and tends to draw more attention from “the fuzz.” If you don’t want HID tickets, stay away from lights over 10,000k!
At 12,000 Kelvin, an HID lamp gives out a violet light. Visibility is significantly poorer than with other colors. 12000k+ lights should never be used for night-time driving. Not only are they annoying to look at, but they significantly decrease your night time visibility, making the road a dangerous place for pedestrians!